[PATCH] dpaa2-eth: Replace strlcpy with strscpy

[PATCH] dpaa2-eth: Replace strlcpy with strscpy

[Jason Wang]

The strlcpy should not be used because it doesn't limit the source
length. As linus says, it's a completely useless function if you
can't implicitly trust the source string - but that is almost always
why people think they should use it! All in all the BSD function
will lead some potential bugs.

But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.

Thus, We prefer using strscpy instead of strlcpy.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
index ad5e374eeccf..2da5f881f630 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
@@ -72,12 +72,12 @@ static void dpaa2_eth_get_drvinfo(struct net_device *net_dev,
 {
 	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
 
-	strlcpy(drvinfo->driver, KBUILD_MODNAME, sizeof(drvinfo->driver));
+	strscpy(drvinfo->driver, KBUILD_MODNAME, sizeof(drvinfo->driver));
 
 	snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
 		 "%u.%u", priv->dpni_ver_major, priv->dpni_ver_minor);
 
-	strlcpy(drvinfo->bus_info, dev_name(net_dev->dev.parent->parent),
+	strscpy(drvinfo->bus_info, dev_name(net_dev->dev.parent->parent),
 		sizeof(drvinfo->bus_info));
 }
 
@@ -191,11 +191,11 @@ static void dpaa2_eth_get_strings(struct net_device *netdev, u32 stringset,
 	switch (stringset) {
 	case ETH_SS_STATS:
 		for (i = 0; i < DPAA2_ETH_NUM_STATS; i++) {
-			strlcpy(p, dpaa2_ethtool_stats[i], ETH_GSTRING_LEN);
+			strscpy(p, dpaa2_ethtool_stats[i], ETH_GSTRING_LEN);
 			p += ETH_GSTRING_LEN;
 		}
 		for (i = 0; i < DPAA2_ETH_NUM_EXTRA_STATS; i++) {
-			strlcpy(p, dpaa2_ethtool_extras[i], ETH_GSTRING_LEN);
+			strscpy(p, dpaa2_ethtool_extras[i], ETH_GSTRING_LEN);
 			p += ETH_GSTRING_LEN;
 		}
 		if (dpaa2_eth_has_mac(priv))
-- 
2.33.0

Re: [PATCH] dpaa2-eth: Replace strlcpy with strscpy

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 30 Aug 2021 21:05:31 +0800 you wrote:
> The strlcpy should not be used because it doesn't limit the source
> length. As linus says, it's a completely useless function if you
> can't implicitly trust the source string - but that is almost always
> why people think they should use it! All in all the BSD function
> will lead some potential bugs.
> 
> But the strscpy doesn't require reading memory from the src string
> beyond the specified "count" bytes, and since the return value is
> easier to error-check than strlcpy()'s. In addition, the implementation
> is robust to the string changing out from underneath it, unlike the
> current strlcpy() implementation.
> 
> [...]

Here is the summary with links:
  - dpaa2-eth: Replace strlcpy with strscpy
    https://git.kernel.org/netdev/net-next/c/995786ba0dab

You are awesome, thank you!
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